Roller



Patented .lune 20, 19.33'

-UNITED STATES PATENT OFFICE JOHANNES ALFTHAN, OF ARLINGTON, AND CARL A. LOFHJELM, OF KEARNY, NEW

JERSEY,'ASSIGNORS TO DU PONT VISCOLOID COMPANY, 0F WILMINGTON, DELA- WARE, A CORPORATION OF DELAWARE ROLLER vApplication led August 8,

This invention relates to machines embodying a roller for contact with the material being operated upon, and to such rollers. More particularly it relates to rollers having a contacting surface provided by a carbohydrate compound derivative, preferably a relatively non-inflammable cellulose derivative such as cellulose acetate. While the invention 1s not confined to the textile industry, it is, for the sake of definiteness described with more particular reference to that art.

In the textile industry, in the process of preparing fiber for the spinning operation, the sliver and roving are subjected to the preparatory operation in preparatory frames whereby the material is doubled, extenuated and slightly twisted. For the accomplishing of this, the machine includes a series of fluted` suitably driven metallic rollers and, above the metallic rollers, a cooperating set of weighted rollers driven by frictional contact from the metallic rollers. The fibers being treated pass between the covered and the fiuted rollers and, the Contact points of the rollers with the goods being spaced farther away in relation to each other in the direction of travel of the fiber than the average length of the fiber, a fiber is not acted upon simultaneously by two sets of rollers, and this causes a sliding effect of the fibers past each other and tends to place the fibers parallel, which is the condition desired. It is the practice of the art, to use for the mentioned weighted frictionally driven rollers, a roller i presenting a relatively soft surface, the roller being made up of a metallic core covered with a layer of woolen cloth and, on the exterior, a layer of leather, thus to give the desired soft surface.

The leather covered roller has been fojmd in practice to have many serious objections. A leather covered roller even when new cannot be operated without a top clearer because the fibers adhereto the leather. A certain amount of friction must exist between the roller and clearer to keep the roller free from fibers and foreign matter, and this friction causes the surface of the roller to become rough which makes the roller less capable of performing the work satisfactorily because 1930. Serial No. 473,885.

the rougher the surface is, the greater is the accumulation of fiber. Therefore, a leather covered roller must frequently be varnished to keep it smooth; and before varnishing the roller must be washed, and during this process many rollers are spoiled. Also the leather cover tends to stretch and work loose on the under layer of woolen cloth (cot). Furthermore the leather is not particularly durable, and has a high initial cost, a high cost for covering the roller, and a high cost of maintenance. We have devised a preparatory frame, and a roller therefor, wherein and whereby the above indicated, and various other difficulties are overcome.

One object of the present invention is to provide a preparatory frame having a roller of such character that difliculties of the type above indicated are eliminated. A further object is to provide a roller for use in preparatory frames, and in other machinery of comparable character, presenting various features of advantage over the rollers of the prior art. To these ends and also to improve generally on apparatus and devices of the general character indicated, the invention consists in the various matters hereinafter described and claimed.

Without restricting the invention thereto it is describedwith reference to the accompanying drawing. In the drawing, Fig. 1 is .a conventional elementary View of that portion of a type of preparatory frame known as fly frame or speeder comprising the driven rollers, the soft-surfaced weighted rollers, and the clearer for such rollers, and embodying the present invention; Figs. 2 and 3 are longitudinal diametrical cross-sectional views of rollers embodyingthe present invention; and Fig. 4 is a longitudinal diametrical cross-sectional view indicating a tool for, and the manner in which, the plastic covering of the present invention may be fitted over and attached to the core of the roller. 1

In general, the invention comprises a roller having a surface of a carbohydrate-compound, desirably non-inflammable, the comln making the roller, a suitable core, preterably a cylindrical metal shell, is covered over its entire cylindrical contacting surface with the covering compound, an intermediate lay- 5 er (or layers) of cushioning material, e. g. telt, being,l desirably, but not necessarily, used Ween the core and the covering compound, telt or the like. giving a padded roller. lnstead of cellulose acetate other preferably relati ely non-inflammable esters ot cellulose such as those made by esteriiication with the higher 'fatty acids or carbocyclic acids, may be used. Est/ers ot other carbohydrates such as starch, may also be used; also carbohy l5 drate ethers such as benzyl and ethyl cellulose. Suitable plasticizers and solvents should, oi course, be selected to suit each case, in accorda ce with the teachings of the art ol? plasticizing carbohydrate compounds.

ln consideration ot the fact that relative non-iniiannnability is desirable, in cases .Vliere, for some particular reason, it is defl to use compound (e. g. cellulose ni- -v`e) belen7 the standard of intended noninilauunability, a suitable selection of tireprooing plasticizers and/or loadingl materials can, ot course, be made.

Referring nonT to the drawing, there is illustrated in l, in an elementary Way with the driving gears etc. omitted, a fly frame l, suoli as intermediate, roving ine or ach traine. is Tstill be understood .oy those skilled in the art, the saine comprises the creol 2, the driven rollers 3, the speeds of which increase troni lett 'to right (in tne f l, the nrictionally driven mated llers i, the clearer of Woolen cloth, and.

spindle G Awith its lyer 7 and bobbin B.

Liera-ting; the roving S is ted between the rollers 3 and Il: Where is doubled, eXtenuated slightly twisted and iinally Wound e bobbin its will be understood, the rollers 3 and 4e and tl e clearer 5 extend crossWise of the machine, and as many sets spindles are provided as are called for by the intended capacity ot the machine. in particular accordance with the invention, the 3 achine embodies rollers d of the particular character new to be described in detail.

5@ Referring; to Figs. 2 8 the roller l einbcdies preferably .metallic shell 8 and a covering tl, an intermediate layer or cot l0 say, it beine used in certain instances, as illustrated in .0' As previously inend.. im.. il? tioned the covering is, inaccordance with the invention, of carbohydrate compound, preferably in 'forni o' a plastic such as cellulose acetate plastic.

The metal roller 8, with or Without a cot, l2@ is covered with the plastic 9 by extruding r. tube plastic directly over the roller, the subsequent shrinkage et the tube causing; the same to grasp the roller tightly; or the tube, previously formed by extrusion, or other G5 means familiar to those skilled in the plastic art, is softened by immersion for a suilicient period, say up to Ql hours, in a softening bath, such as a mixture of Water and acetone, or Water, or acetone and glycerine, or Water and mono-methyl ether of ethylene glycol, or various other diluted solvents. After the plastic is thus soitened it is stretched and slipped over the roller whereupon, alter evaporation olE the softening materials, the tube shrinks and adheres lirinly to the roller. (A suitable cement may be used it desired). 'thereafter the covered roller is subjected to a seasoning operation lor seasoning the plastic, and finally is lground down to the center. @ther methods ot covering` the roller may also be used, for example plastic sheet ing may be rolled about the metal shell and cemented thereto, or a thiol; dope ot the plastic dissolved in suitable solvents may be applied by spraying, dipping,` or brushing.

the mentioned method, ot stretching the lastic tube and slipping it over the central hell to shrink thereon, may convenienthY be Aerfornied with the tool illustrated in liu'. s. Such tool, designated generally as ll. comprises the thin Walled cylinder l2, prel erL bly of metal, and the nose i3. '.lhc portion l2 is of a. proper diainetc and length to closely receive the shell 8 to be covered. ln use. the nose 13 is inserted in the softened plastic tube 9 and the tube slid alongthe nose, in the meantime being stretched, until it is received on the portion in register with the shell 8 With the portion i2 shell. The tube and neously moved tothe right (in. y. them from the tool, and the 'tube shrinks upon the shell d as ai'foresaid.. This method also applicable in cases Where the roller is First provided with a cot ceuujaited thereon.

l/lhile rollers embodying the in i ention in ary comprise various carbohydrate compound plastics, plastic having ba e. of cellulose acetate, preferably ot the de ordinarilyv used in the manufacture of plastic, has been found particularly satisfactory, in 'view ot relative non-inllaminabilit-y and freedom from lire hazard and other factors. las preriously indicated, it is desirable to employ the compound in the form ot a plastic. By of illustration merely., and not by way of limitation, the composition may be (parts by Weight) cellulose acetate 75, dibutyl phthalate l5, and dimethyl phthalate l0. ln the usual Way of the cellulose ester plastics art, the ingredients are inacerated in a. dough mixer with a suitable Volatile solvent or solvent mixture, :r example acetone alone or a mixture ot et acetate and alcohol, in suitable quantity, and a't-er proper mixing the composition is filtered and rolled, and is.

pressed for slicing; into sheets, or is extruded into tubes. ptionally, of course, the nonvolatile ingredients may be combined with the cellulose ester in any other suitable manreino/is ner and the resulting mass given a desired form by heat and pressure Without the presnence of volatile solvent.: s p

"lln place of the plasticizers, dibutyl phthalate and dimethyl phthalate, suggested above, many other plasticizeers or softeners may, of course, be used, many examples of such plasticizers being described in the literature and in the patents, Suchfor example as triphenyl phosphate, triacetin, ethyl paratolulene sulphonamide, acetanilid, methyl acetanilid, ethyl acetanilide and so forth.

As Will be evident, it is often preferable to vary the composition in consideratiun of Whether or not the roller is to embody a cot l0, using a sofr plastic in cases Where no cot is resent, thus compensating for the absence ot the cot. A greater degree of softness may, of course, be obtained by the use of a high plasticizer content or by the addition of certain oils, e., g. castor oil, natural resins, e. g. gum elemi, or synthetic resins, e. g. certain of the glyptalsfor cyclic sulphonamide resins. icetanilid and its Valkyl derivatives are useful for imparting softness. l he above described composition of cellulose acetate and plasticizers 25% may be taken as an example of a relatively hard plastic which, although it may be used in rollers Without a cot, is more particularly applicable to rollers including a cot. Examples of compositions yielding soft plastics, particularly useful for rollers Without a cot are (parts by Weight) cellulose acetate. 50,' triacetine 35 and diethyl phthalate 15; and cellulose acetate 50, dimethyl phthalate d0, acetanilid 10,

The thickness of the plastic on the roller may be varied but, generally speaking, it has been found that a thickness of from .0l to .25 inch is desirable. l/lhere no padding (cot) is present and a soft plastic is used the tvall thickness may Well beheavier than inJ cases Where the roller is padded. rlhus, Where no padding is used, a Wall thiclmess in the neighborhood of .25 inch is recommended; and for a padded roller a Wall thickness of .0l to .07 inch is recommended With a cot of the usual thickness.4 A Wall thickness of .01 to .02 inch will give considerable cushioning Whereas a Wall thickness' of '.04 to .O7 inch will give a more rigid coating. The amount of cushioning can, of course, be varied by changing the wall thickness of the plastic, since the thinner the plastic Wall surrounding the padding, the more evident will be the cushioning eect of the padding itselfn As an alternative ir addition to the previously described methods of applying the plastic on the roller, a dope may be deposited directlyon the cot, or a cellulose compound varnish may be applied to the leather cover of the ordinary roller,loy dipping, painting or spraying the surface.

Rollers of the present invention, more paraan c@ ticularly, but not necessarily, of cellulose acetate plastic, are applicable in the manufacture of yarn from cotton, Wool, silk, rayon, flax and so forth; and also in industries Where at the present time Yrubber covered rollers are used, as in the manufacture of tiles. A cellulose acetate plastic. roller has the advantage ofbecoming smoother the longer it runs in contact With the clearer, and therel fore the i'iber has less tendency to adhere thereto. 'lhe clearer is for the purpose of picking up any iibers or foreign matter that may be carried along with the rollers, as this is of great importance for the prevention of roller lap; and the mentioned smoothness of the plastic roller enables the clearer to better perform its functions.

rlfhenature of cellulose acetate plastic is such as to repel the fibers, thus preventing a roller lap. lFurther, by repelling the liber thereis less accumulation of fibers and foreign matters on the clearers, hence less slugs and better yarn. Also, the plastic covered roller, unlike theleather covered roller, has no joint or seam, and also the plastic is more durable than leather and the initial costs, covering costs and maintenance costs are greatly reduced by the plastic.v

l/lhile the invention has been described Y With more particular reference to a ily frame, it Will be understood that it is applicable to other preparatory frames such as lap ma-k tures.

' JOHANNES ALFTHAN. CARL A.. LOFHJELM.

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